Cylinder lock



M. LEISER CYLINDER LOCK July 13, 1965 Filed Nov. 5, 1962 INVENTOR. M4 ra/v 15/552 United States Patent 3,194,034 CYLINDER LOCK Milton Leiser, 305 E. Mount Eden Ave., New York, N.Y. Filed Nov. 5, 1962, Ser. No. 235,252 Claims. ((31. 70-358) The present invention relates generally to tumbler locks and specificaly to a lock which offers greatly improved protection against picking.

Although conventional cylinder or tumbler locks are generally accepted as providing superior protection against lock picking, in many instances it has been found that even these devices do not afford sufficient protection. The .vending machine industry, for example, provides situations'wherein conventional locks are used to safeguard cash boxes which often contain reasonably large amounts of money. Because the vending machines are unattended, they provide excellent opportunities for thievery by way of picking the cash box locks.

The conventional cylinder lock includes a cylinder body within which is rotatably positioned a key plug. Aligned tumbler bores are formed within the key plugand the cylinder and split pins or tumblers are positioned within these bores. A key, of the correct shape, when inserted into the key plug, will align the tumblers with the border between the key plug and the cylinder to free the key plug for rotation. Such locks may be opened without keys by any means which will properly align the split pins. Although such tumbler locks are constructed with relatively high degrees of precision, they are nevertheless subject to expert thievery.

Accordingly, it is the general object of the present invention to provide a cylinder lock which may be opened only by the key produced specifically for that lock. More particularly, it is an object of the present invention to provide a cylinder lock which may not be opened by a thief in the way that conventional locks may be picked.

In accordance with one illustrative embodiment of the present invention, there is provided a cylinder lock formed with a cylinder having a central cavity and a two-part key plug rotatably positioned within the cylinder. The twopart key plug includes a plug sleeve housed within the cylinder and a key plug housed within the plug sleeve. A pair of oppositely directed and aligned longitudinal rows of tumbler bores are provided within the cylinder and within the two-part key plug. The key plug is mounted within the plug sleeve for rotation through 180 from a locked to a semi-locked position and the plug sleeve is mounted for rotation within the cylinder through 180 from said semi-locked position to an unlocked position. A further tumbler bore is formed within one of the rows of tumbler bores in the cylinder, the plug sleeve and central key plug. The portions of the further tumbler bore are in registry when said elements are in the semi-locked position; the portions of the further tumbler bore being 180 out of registry when the key plug is in its locked position. Three-piece tumblers are positioned in each of the tumbler holes in association with conventional tumbler bias means to bias the tumblers toward the center of the lock. With the insertion of the pro-per key into the lock, one set of split portions of the three-part tumblers are aligned at the boundary between the key plug and the key sleeve such that the key plug may be rotated to its semi-locked position to thus bring the portions of the further tumbler bore into registry. Further placement of the correct key within the key plug is then efiective to align the three part tumblers at the boundary of the plug sleeve and the cylinder such that the two-part key plug may be rotated within the cylinder through 180 to the unlocked position.

The above brief description, as Well as further objects, features and advantages of the present invention, will be best appreciated by reference to the following detailed 3, 1 94,034 Patented July 13, 1965 description when taken in conjunction with the accompanying drawings wherein:

FIGURE 1 is a central sectional View of a cylinder lock according to the present invention shown in its fully locked position and with the key inserted;

FIGURE 2 is a view similar to FIGURE 1 with the key and central key plug shown rotated through to the semi-locked position;

FIGURE 3 is a transverse sectional view taken along the line 33 of FIGURE 2 and looking in the direction of the arrows; and,

FIGURE 4 is an elevational view from the rear of the cylinder lock.

Referring now specifically to the drawings, there is shown a cylinder lock according to the present invention generally designated by the numeral 10 which includes a cylinder or a casing 12 and a two-part plug 14 including the central key plug 16 and a plug sleeve 18. The cylinder 12 may be any external configuration desired and is formed with a central cylindrical cavity. The two part key plug 14 is positioned within this cavity with the plug sleeve 18 in intimate contact with the walls of the internal cavity and mounted for rotation therein andthe central key plug 16 positioned within and in intimate contact with the internal walls of the plug sleeve 18 and mounted for rotation with respect thereto. Thus, the central key plug 16 may be rotated within the plug sleeve 18 and the plug sleeve 18 may be rotated within the cylinder 12.

The central key plug 16 and plug sleeve 18 are retained against longitudinal movement by means of the complementary annular lips and grooves 20, 22 formed between the key plug16 and the plug sleeve 18, and the plug sleeve 18 and cylinder 12, respectively. At the other end, the key plug 14 is'retained by the provision of a nut 24 threadily secured to a stud 26 which extends rearwardly from the central key plug 16. An integral washer 28 on the nut 24 bears against an annular member 30 connected to the plug sleeve 18 which in turn bears against the annular ring 32 which is in contact with the rear of the casing 12. Thus the lip and grooves 20, 22 at one end and the locking nut 24 at the other provide positive securement of the key plug 14 longitudinally within the cylinder 12.

A plurality of tumbler bores, generally designated by numeral 40, are formed within the cylinder lock 10 and extend in registry through the two parts of the key plug 14 and the casing 12. The tumbler bores 40 are arranged in a pair of evenly spaced longitudinal rows, generally designated herein by the symbols A and B, which directly oppose each other such that the bores of row A are directly in line with the bores of row B. In the present illustrative showing, each row A, B, is provided with six tumbler bores 40.

A further tumbler bore, designated generally by the numeral 42, and designated more specifically by the numerals 42a, 42b and 420 for the portion of the bore 42 in the cylinder 12 the plug sleeve 18 and the central key plug 16, respectively, is formed in spaced longitudinal alignment with the bores 49 at the rearward end of the cylinder lock 10. In the locked position of the cylinder lock 10 as illustrated in FIGURE 1, it will be noted that the additional bore 42 is not complete since one portion of the bore 42c within the central key plug 16 is 180 out of registry with the remainder o fthe bore 42 such that a solid portion of the key plug 16 blocks the access to the bore 42a, 42b.

Positioned within each of the bores 40, 42 are threepart tumblers, labeled herein 50, 52 and 54, with the designation 50 indicating the innermost portion of each tumbler, and a biasing spring 56 positioned outwardly of the tumblers and between the tumblers and the base of the tumbler bores 40. In accordance with normal tumbler lock technology, a shoulder 58 is formed at the innermost end of the tumbler bores'providing the innermost limit of the travel of the tumblers. Further in acof guidechannels 62 on opposite sides of the keyslot 7 though its associated dog and further unlocking from the 6t). A key 64 is provided with conventional guide ridges 66 for reception within the guide channels 62. The key 64 is a double bitted key and is provided with bits 68 and interspaced lands on one side andfurther bits 70 and appropriate land surfaces on the other. key 64 into the key slot 60 brings the various bits 68, 7t and lands of the'keyinto engagement with the tumblers to position same along the length of thetumbler bores i The features of the cylinder lock 10 according to the present invention will be best understood by consideration of the operation of the lock 10. In FIGURE 1, the device is shown in its locked position with the key 64 inserted into the keyway 60. It will be noted that the various positions of the respective bores 40 are normally in alignment but that the additional bore 42 is not in alignment,'the portion 420 being 180 from the portions 42a and 42b. The lock 10 cannot possibly be picked from this position since even if the tumblers 5t), 52, 54. could be aligned within the bores 40, no alignment of the tum blers within the bore 42 could be, accomplished since. that bore is sealed'off by asolid portion of the key central Insertion of the tion as shown in this illustrative embodiment. fore, the following claims should be interpreted broadly key plug 16. Continuing with the description of the un locking operations of the device 10, the insertion of the key 64 into the lock aligns the tumblers so that one of the splits of each of thetumbler groups is aligned with the interface between the central key plug 16 and the plug sleeve l8 such that the central key plug 16 may be roand 2. The flat land portion 72 is suificient to pass over 1 the innermost portion of the tumbler 59 within the tumbler bore 42c. V

With the reinsertion of the key 64 into the lock 10 when the device is in its semi-locked position ofFIGURE 2; the interrelated heights of the various land portions on the key and the split tumblers again cooperate to produce an alignment between the split tumblers and the interface between the plug sleeve 18 and the cylindrical casing 12 and, at the same time, preventing the relative movement.

between the parts of the two part plug 14. Rotationzof the key 64 will then be effective to rotate the assembled key plug 14 and therefore the plug sleeve 18. 7 Rotation of the plug sleeve 18 will be efiective to rotate the annular member 30, secured to. the plug sleeve 18 as by welding as shown at 31, such that the dog 33 is rotated through 180 to perform the desired unlocking function. 7

It will be appreciated that the configuration of the lock 10 inits completely unlocked position will be similar to that in FIGURE 2 with the entire key plug 14 rotated through 180" in that position will securely lock the device into its. unlocked position. To lock the lock, the key is thenreinserted and turned to 180, removed and turned again, reinserted and once more turnedto bring the lock'from the semi-locked position of FIGURE 2 to the completely locked position of FIGURE 1.

l .A variety'of modifications of the disclosed locking device may be easily accomplished. For'example, it is a relatively simple matter to provide a further locking dog in engagement with the center key plug 16 such thatthe movement from the fully locked to the semi-locked position will be effective to .operate one unlocking feature Removal of the'key from the keyway 6t} embodiment of my present invention.

invention. 1

semi-locked to the unlocked position will be effective as f described above to operate the main locking dog 33.

It will be appreciated that the above described invention provides a cylinder, tumbler type lock, incorporating novel constructional features which greatly enhance the characteristicot tumbler locks with regard to versatility of operationand specifically with regard to the anti-pick qualities of thelock. Specifically, skilled'thieves have been able to pick even the prior art opposed tumbler type of lock. However, with the provisionof a dead tumbler, which is uncovered only by means of going through the first unlocking operation, it is made. impossible for thieves tosimply align all the tumblers and open the lock since access to'one" of the tumblers is blocked by solid metal.

The foregoing is 'a description of just one illustrative It should be appreciated that the concepts of my invention may be incorporated in other locks by varying the details of construc- Therein a manner consistent with theispirit and scope of the Iclaim: j .1. A cylinder lock comprising a cylinder having a central cylindrical cavity and formed with a pair of oppositely directed andaligned longitudinal rows of tumbler bores,

a two-part key plug'includin'g a plug sleeve received withi in 'said 7 cylinder in engagement with the walls of said cavity for axial rotation-within said cylinder, and a central key plug having an axial key slot formed therein and received within said plug sleeve for axial rotation therein, said central keyrplug being rotatable through 180 within 'said plug sleeve from a locked position to a semi-locked position and, said central key plug and plug sleeve being rotatable through 180 within saidv cylinder to an un- 7 locked position, saidtwo-part key plug having tumbler bores formed therein in alignment with the tumbler bores of said cylinder, said cylinder having one further tumbler bore formed within one of said rows, said plug sleeve and said central key plug having a. further tumbler bores formed therein in longitudinal alignment with said one further cylinder tumbler bore, said plug sleeve and said central key plug being rotatable to bring said further tumbler bores into radial registry in said semi-locked position, three-piece tumblers, including a first tumbler piece at an inner position, a second tumbler piece at a middle positionand a third tumbler piece at an outer position,

housed in each of said tumbler bores, and means in said tumbler bores biasing said tumblers toward the center of said cylinder-lock, the interfaces between said first and second tumbler pieces of said three-piece tumblers being aligned with the edge of said central key plug .and said plug sleeve when the associated key is placed within said central key plug in one orientation and when said lock der being covered from access through said key slot when the lock is in the locked position by a solid portion of said central key plug and being in communication with said key slot only when said 'centralkey plug is rotated 180 with respect to said plug sleeve from the locked to the semi-locked position. 'i

2. A cylinder lock comprising a cylinder having a central cavity and formed with a pair'of oppositely directed and aligned longitudinal rows of tumbler bores, a two-part key plug including a plug sleeve received within said cylinder in engagement with the walls of said cavity for rotation within-said cylinder, and a central key plug having a keyway formed along the axis thereof and received within said plug sleeve for rotation therein, said central key plug being rotatable through 180 within said plug sleeve from a locked position to a semi-locked position and said central key plug and plug sleeve being rotatable through 180 within said cylinder to an unlocked position, said two-part key plug having tumbler bores formed therein in alignment with the tumbler bores of said cylinder, said cylinder having one further tumbler bore formed within one of said rows, said plug sleeve and said central plug each having a further tumbler bore formed therein, said further cylinder tumbler bore being in longitudinal alignment with said further tumbler bores in said plug sleeve and said central plug and being in communication with said keyway only when said plug sleeve and said central plug are in said semi-locked position, a locking dog secured to said plug sleeve, three-piece tumblers in each of said tumbler bores, and spring means in said tumbler bores biasing said three-piece tumblers toward the center of said cylinder lock, interfaces between the parts of said three-piece tumblers being aligned with the edge of said center plug and said plug sleeve when a key of proper profile is placed within said center plug in a first orientation with said lock in the locked position and being aligned with the edge of said plug sleeve and said cylinder when a key is placed in said central plug in a second orientation and when said lock is in its semi-locked position.

3. A lock comprising a cylinder, a sleeve mounted rotatably within and coaxial to said cylinder, at key plug secured within and coaxial to said sleeve and rotatable through 180 within said sleeve between a normally locked position and a semi-locked position, said sleeve and said key plug being secured against coaxial movement with respect to said cylinder, a keyway formed along the axis of said key plug, a plurality of alignedtumbler bores formed within said lock radially extending in opposite directions from said keyway through said sleeve and into said cylinder, a single further tumbler bore formed through said sleeve and said key plug and extending into said cylinder, said further tumbler bore extending in only one direction from the axis of said lock, the portions of said further tumbler bore in said cylinder and said sleeve being in communication with said keyway only when said plug is turned 180 from its locked position, a three-piece split tumbler and tumbler spring positioned in each of said tumbler bores, said split tumblers being coordinated with an appropriate key such that interfaces between respective pieces of said tumblers are aligned with the interface betwen the key plug and the sleeve when the key is inserted within the keyway in one orientation and such that other interfaces between respective pieces of said split tumblers are aligned with the interface between the sleeve and the cylinder when the key is inserted within the keyway in another orientation.

4. A lock and key comprising a cylinder, a sleeve mounted for rotation within and coaxial to said cylinder between a normally locked position and :an unlocked position, a key plug secured within and coaxial to said sleeve and rotatable through 180 within said sleeve between a normally locked position and a semi-locked position, said sleeve and said key plug being secured against coaxial movement with respect to said cylinder, a keyway formed along the axis of said key plug, two rows of evenly pieced and aligned tumbler bores formed within said lock radially extending in opposite directions from said keyway through said sleeve and into said cylinder, a single further tumbler bore formed through said sleeve and said key plug and extending into said cylinder, and positioned within one of said rows, said further tumbler bore extending in only one direction from the axis of said lock, the portions of said further tumbler bore in said cylinder and said sleeve being in communication with said keyway only when said plug is turned 180 from its locked position to its semi-locked position, a three-piece split tumbler and tumbler spring positioned in each of said tumbler bores, a double bitted key sized to be received within said keyway, said split tumblers being coordinated with said key such that a first set of interfaces between respective pieces of said tumblers are aligned with the interface between the key plug and the sleeve when the key is inserted within the keyway in one orientation with said sleeve with locked position and such that another set of interfaces between respective pieces of said split tumblers :are aligned with the interface between the sleeve and the cylinder when the key is inserted within the keyway in another orientation and when the key plug is in its semi-locked position.

5. The combination of a cylinder lock and ke the cylinder lock comprising a cylinder having a central cylindrical cavity and formed with :a pair of oppositely directed and aligned longitudinal rows of tumbler bores, a twopart key plug including a plug sleeve received within said cylinder in engagement with the walls of said cavity for axial rotation within said cylinder, and a central key plug having an axial keyway formed therein and received within said plug sleeve for axial rotation therein, said centnal key plug being rotatable through 180 within said plug sleeve from .a locked position to a semi-locked position and said central key plug and plug sleeve being rotatable as a unit through 180 within said cylinder to an unlocked position, said twoapart key plug having turnbler 'bores formed therein in alignment with the tumbler bores of said cylinder, a locking dog secured to said plug sleeve, three-piece tumblers including a first tumbler piece at an inner position, a second tumbler piece at a middle position and a third tumbler piece at an outer position,

housed in each of said tumbler bores, and spring means in said tumbler bores biasing said tumblers towand the center of said cylinder lock, the key having two sets of oppositely facing bits engageable with the tumblers in the oppositely directed tumbler bores, the interfaces between the first and second tumbler pieces of said three-piece tumblers being [aligned with the edge of said central key plug and said plug sleeve when the key is placed within said central key plug in a first orientation and when said lock is in the locked position and the interfaces of said second and third tumbler pieces being aligned with the edge of said plug sleeve and said cylinder when the key is placed in said central key plug in a second orientation and when said lock is in the semi-locked position.

References Cited by the Examiner UNITED STATES PATENTS 830,013 9/06 Shaw 3 40 899,955 9/08 Collins 7037-3 1,565,557 12/25 Fremon 70"339 ALBERT H. KAMPE, Primary Examiner. 

5. THE COMBINATION OF A CYLINDER LOCK AND KEY, THE CYLINDER LOCK COMPRISING A CYLINDER HAVING A CENTRAL CYLINDRICAL CAVITY AND FORMED WITH A PAIR OF OPPOSITELY DIRECTED AND ALIGNED LONGITUDINAL ROWS OF TUMBLER BORES, A TWOPART KEY PLUG INCLUDING A PLUG SLEEVE RECEIVED WITHIN SAID CYLINDER IN ENGAGEMENT WITH THE WALLS OF SAID CAVITY FOR AXIAL ROTATION WITHIN SAID CYLINDER, AND A CENTRAL KEY PLUG HAVING AN AXIAL KEYWAY FORMED THEREIN AND RECEIVED WITHIN SAID PLUG SLEEVE FOR AXIAL ROTATION THEREIN, SAID CENTRAL KEY PLUG BEING ROTATABLE THROUGH 180* WITHIN SAID PLUG SLEEVE FROM A LOCKED POSITION TO A SEMI-LOCKED POSITION AND SAID CENTRAL KEY PLUG AND PLUG SLEEVE BEING ROTATABLE AS A UNIT THROUGH 180* WITHIN SAID CYLINDER TO AN UNLOCKED POSITION, SAID TWO-PART KEY PLUG HAVING TUMBLER BORES FORMED THEREIN IN ALIGNMENT WITH THE TUMBLER BORES OF SAID CYLINDER, A LOCKING DOG SECURED TO SAID PLUG SLEEVE, THREE-PIECE TUMBLERS INCLUDING A FIRST TUMBLER PIECE AT AN INNER POSITION, A SECOND TUMBLER PIECE AT A MIDDLE POSITION AND A THIRD TUMBLER PIECE AT AN OUTER POSITION, HOUSED IN EACH OF SAID TUMBLER BORES, AND SPRING MEANS IN SAID TUMBLER BORES BIASING SAID TUMBLERS TOWARD THE CENTER OF SAID CYLINDER LOCK, THE KEY HAVING TWO SETS OF OPPOSITELY FACING BITS ENGAGEABLE WITH THE TUMBLERS IN THE OPPOSITELY DIRECTED TUMBLER BORES, THE INTERFACES BETWEEN THE FIRST AND SECOND TUMBLER PIECES OF SAID THREE-PIECE TUMBLERS BEING ALIGNED WITH THE EDGE OF SAID CENTRAL KEY PLUG AND SAID PLUG SLEEVE WHEN THE KEY IS PLACED WITHIN SAID CENTRAL KEY PLUG IN A FIRST ORIENTATION AND WHEN SAID LOCK IS IN THE LOCKED POSITION AND THE INTERFACES OF SAID SECOND AND THIRD TUMBLER PIECES BEING ALIGNED WITH THE EDGE OF SAID PLUG SLEEVE AND SAID CYLINDER WHEN THE KEY IS PLACED IN SAID CENTRAL KEY PLUG IN A SECOND ORIENTATION AND WHEN SAID LOCK IS IN THE SEMI-LOCKED POSITION. 